Vacuum feed-through assemblies are used in any system or application that requires the transfer of power or current through in a vacuum environment. Present state of the art vacuum feed-through assemblies are based on brazing one end of a stainless steel tube or bellows to the outer diameter of a ceramic ring, which is brazed to the outer diameter of a copper rod. The brazing operations required to join these components together to make a vacuum tight joint are complex, time-consuming, and expensive. Further, the ceramic ring is very brittle and when the joint is subjected to shock or vibration loads, the ceramic often fractures or the joint fails.
It is expensive and time-consuming to perform brazing in ovens and the ceramic is expensive. Sometimes, especially when used in assemblies with cold temperatures, when there are movements and sideways loads, the ceramic breaks and a failure occurs. A failure is significant because the vacuum is lost. The problem of cracking and leaking that occurs when using ceramic seal is unacceptable.